US4756792A
Expired / Lapsed
US
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Method for vapor-phase epitaxial growth of a single crystalline-, gallium arsenide thin film
Assignee: Mitsubishi Chemical Corp
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Filing: 1986-09-05
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Granted: 1988-07-12
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Expires: 2006-09-05
Abstract
Abstract In a GaAs epitaxial wafer including, for example, two epitaxial layers having high and low carrier concentrations, the carrier concentration of the low carrier concentration layer is liable to greatly vary, so that wafers suitable for FETs and Schottky barrier diodes operated at UHF and SHF are produced at only a low yield. This drawback is eliminated by adjusting the heating temperature of GaAs substrate to 690° to 730° C. during the growth of the low carrier concentration layer.
Inventors
- 👤 Hisanori Fujita
- 👤 Masaaki Kanayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:12
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; C; C30; C30B; C30B25/00; C30B25/02; C30B29/00; C30B29/10; C30B29/40; C30B29/42; H10P14/24; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/2926; H10P14/3438; H10P14/3441; H10P14/3442; H10P14/36
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
167 words
A method for vapor-phase epitaxial growth of a single crystalline gallium arsenide thin film, wherein, on a single crystalline gallium arsenide substrate, said single crystalline gallium arsenide thin film consisting of a plurality of layers having carrier concentrations different from one another is epitaxially grown from a vapor phase, and further, a (Ga)/(As), which is a ratio of a number of gallium atoms to a number of arsenic atoms contained in unit volume of gases used for the vapor-phase epitaxial growth, is adjusted to be greater than 1 during growth of a layer(s) having a low carrier concentration and is adjusted to be smaller than 1 during growth of another layer(s) having a high carrier concentration, characterized in that, a temperature of said single crystalline gallium arsenide substrate is held at a first temperature of from 690° to 730° C. during formation of said low carrier concentration layer(s), and at a second temperature of from 735° to 830° C. during formation of a high carrier concentration layer(s).
Claim 2
Independent Claim
167 words
A method for vapor-phase epitaxial growth of a single crystalline gallium arsenide thin film, wherein, on a single crystalline gallium arsenide substrate, said single crystalline gallium arsenide thin film consisting of a plurality of layers having carrier concentrations different from one another is epitaxially grown from a vapor phase, and further, a (Ga)/(As), which is a ratio of a number of gallium atoms to a number of arsenic atoms contained in unit volume of gases used for the vapor-phase epitaxial growth, is adjusted to be greater than 1 during growth of a layer(s) having a low carrier concentration and is adjusted to be smaller than 1 during growth of another layer(s) having a high carrier concentration, characterized in that, a temperature of said single crystalline gallium arsenide substrate is held at a first temperature of from 690° to 730° C. during formation of said low carrier concentration layer(s), and at a second temperature of from 735° to 830° C. during formation of a high carrier concentration layer(s).
Claim 3
Dependent Claim
24 words
A method according to claim 1, wherein a first temperature during forming of said low carrier concentration layer is from 700° to 730° C.
Claim 4
Dependent Claim
26 words
A method according to claim 1 or 2, wherein a second temperature during forming of said high carrier concentration layer is from 735° to 760° C.
Claim 5
Dependent Claim
27 words
A method according to claim 1, wherein a [Ga]/[As] is held in a range of from 2 to 10 during forming of said low carrier concentration layer.
Claim 6
Dependent Claim
27 words
A method according to claim 1, wherein a [Ga]/[As] is held in a range of from 0.1 to 0.8 during forming of said high carrier concentration layer.
Claim 7
Dependent Claim
24 words
A method according to claim 1, wherein said low carrier concentration layer has a carrier concentration of from 1×10 18 cm -3 or less.
Claim 8
Dependent Claim
23 words
A method according to claim 6, wherein said low carrier concentration layer has a carrier concentration of 1×10 15 cm -3 or less.
Claim 9
Dependent Claim
22 words
A method according to claim 7, wherein an epitaxial wafer consisting of said thin film and substrate is used for an FET.
Claim 10
Dependent Claim
26 words
A method according to claim 6, wherein said low carrier concentration layer has a carrier concentration of from 1×10 16 to 1×10 18 cm -3 .
Claim 11
Dependent Claim
24 words
A method according to claim 9, wherein an epitaxial wafer consisting of said thin film and substrate is used for a Schottky barrier diode.
Claim 12
Dependent Claim
39 words
A method according to claim 7 or 9, wherein said method is repeated at least ten times while maintaining gas phase-epitaxial conditions as constant, thereby obtaining a carrier concentration of said low carrier concentration layer which varies within ±10%.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-07-12 | 1992-01-11 | 1992-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-12 | 1996-01-11 | 1996-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-12 | 2000-01-11 | 2000-07-12 | $7700.00 | Window Closed / Lapsed |